As is well known, a silver halide multilayer color photographic material has on a support such as a cellulose ester film or a polyester film, in succession, a red-sensitive silver halide emulsion layer containing a non-diffusible cyan image-forming coupler, a green-sensitive silver halide emulsion layer containing a non-diffusible magenta image-forming coupler, and a blue-sensitive silver halide emulsion layer containing a non-diffusible yellow image-forming coupler.
In the color negative photographing light-sensitive material having the above-described layer structure, the factors governing the color reproducibility are the following two factors.
One of the factors is an interlayer effect. In a silver halide multilayer color photographic material, it is known to add so-called DIR couplers which form or release a development inhibitor or a precursor thereof by causing a coupling reaction with the oxidation product of a color developing agent, and by inhibiting the occurrence of development of other silver halide emulsion layers with the development inhibitor released from the DIR compound, the interlayer effect is realized, whereby the effect of improving the color reproducibility is obtained.
Another factor is a spectral sensitivity distribution. In the layer structure of a silver halide multilayer color photographic material, it is usual that a red-sensitive emulsion layer has a sensitivity for light of wavelengths of from 550 to 680 nm, a green-sensitive emulsion layer for light of wavelengths of from 480 to 580 nm, and a blue-sensitive emulsion layer for light of wavelengths of from 400 to 510 nm. The color sensitivities of the emulsion layers are not always constant in each spectral wavelength region, each emulsion layer has a different spectral sensitivity distribution according to the spectral sensitizer(s) and other material(s), and the positions of the peaks of the spectral sensitivity distributions and the duplications of the foot portions thereof differ according to the selection or combination of the foregoing materials, which becomes another factor governing the color reproducibility of the color photographic material.
Recently, for color photographic materials, various improvements in DIR compounds and improvements in the techniques of using them have been made, and with such technical progress, a further improvements in color reproducibility has been investigated.
A method of adding DIR compounds for improving the color reproducibility of conventional color photographic materials is known, as described in U.S. Pat. No. 3,227,554, etc. It is generally known that a DIR compound gives an interlayer effect in multilayer color photographic materials, but the DIR compounds described in the above-described U.S. patent, etc., show only a small effect on improving the color reproducibility by the interlayer effect. If a large amount of such a DIR compound is used for improving the color reproducibility, there occurs such disadvantages that the development of the emulsion layer itself containing the compound is delayed, the gradation is lowered, and the maximum colored density and the effective sensitivity are lowered.
For eliminating the above-described disadvantages and improving the color reproducibility, a method of improving the color reproducibility by increasing the interlayer effect using diffusible DIR couplers is disclosed in Japanese Patent Application (OPI) No. 131934/84 (the term "OPI" as used herein refers to a "published unexamined Japanese patent application").
That is, Japanese Patent Application (OPI) No. 131934/84 discloses a silver halide color photographic material containing development inhibitor-releasing materials capable of releasing a development inhibitor having a magnitude of diffusibility of from 0.4 to 0.95 by causing a reaction with the oxidation product of a developing agent during development.
However, in the case of improving the color reproducibility of color photographic materials using the DIR couplers disclosed in the above patent application, the amount thereof may be small for obtaining a high-saturation color reproducibility, but the DIR couplers have a disadvantage that the reproduction of shades of photographic subjects, in particular, the reproduction shades of red subjects, is insufficient.
Also, a method is known for improving the saturation of a color photographic material by changing the spectral sensitivity distributions of the silver halide emulsion layers to reduce the duplication of the spectral sensitivity distributions of them, thereby improving the color separation, but this method has a disadvantage that the reproduction of the hue of an intermediate color is not faithful.
Thus, it has been desired to improve color photographic materials by eliminating these disadvantages.